What term describes a non-native species that causes harm in an ecosystem?

• A. Keystone species
• B. Pioneer species
• C. Invasive species
• D. Heredity

Answer: (C)

Invasive species are non-native organisms that cause harm when they enter a new ecosystem. They often spread rapidly, outcompete native species for resources, alter habitats, disrupt food webs, and can bring diseases, leading to declines in biodiversity and changes in ecosystem function. It’s not just being non-native that defines them, but the negative impact they have on the environment.

Keystone species are influential due to their ecological role, regardless of whether they are native or introduced. Pioneer species are the first to colonize disturbed areas, helping initiate succession but not defined by harm. Heredity refers to the passing of traits from parents to offspring, which is a genetic concept, not a type of species.